Speak to your GP. has she recently been unwell...fever. ..etc...thinking auditory hallucinations. Has she hit her head recently etc..Is she confusing the monologue of her own internal thoughts that can run amuckor is there more going on from a mental health point of view or medically. Whatever the answer she needs to be checked over. Has she said what the voices say?

Yes, my dc started to about a year ago now. They come and go these days. It can be really normal for some children! It can be a form of social imagination, or a response to something that has happened to them. Can even be caused by an infection, or an injury. Please have a chat with your GP. They will want to know if the 'voice' seems to be coming from inside or outside the head & if, say, the child is aware. My DC started talking to herself often in the third person. She thought we could hear what she heard. Good luck!